8 Troubleshooting
8.1
Temporary and permanent faults
The codes on the display indicate two types of fault: volatile and
permanent. The first item shown on the display is a letter followed by a
two-digit number. The letter indicates the type of fault: temporary (H) or
permanent (E). The number indicates the group in which the fault that has
occurred is classified according to its impact on safe and reliable
operation. The second item shown flashes alternately with the first and
consists of a two-digit number that indicates the type of fault which has
occurred (see the following fault tables).
TEMPORARY FAULT (A/H.x.x.)
A temporary fault is shown on the display by the letter “A” or “H” followed
by a number (group). A temporary fault is a type of fault that does not
cause a permanent stoppage of the boiler. It has the following
characteristics:
A: The appliance continues to operate. It disappears as soon as the cause
has been resolved.
H: Disappears when the error condition is removed, in some cases even
after 10 minutes.
PERMANENT FAULT (E.x.x)
A permanent fault is shown on the display by the letter "E" followed by a
number (group). Press the RESET button for one second. If faults are
shown frequently, contact our authorised technical assistance centre.
E: Stoppage, reset required..
8.2
Error codes
8 Troubleshooting
Tab.11 List of temporary faults
DISPLAY
DESCRIPTION OF TEMPORARY FAULTS
CAUSE – Check/Solution
An installer is required for most checks and solu
tions.
Group
code
Specific
code
H.00
.42
Pressure sensor open/faulty
SENSOR/CONNECTION PROBLEM
Check the operation of the pressure sensor
Check the sensor/PCB connection
H.01
.00
Temporary communication failure in the PCB
The error is resolved automatically
H.01
.05
Maximum temperature difference value between flow
and return reached.
INSUFFICIENT CIRCULATION
Check the boiler/installation circulation
Activate a manual venting cycle
Check the installation pressure
OTHER CAUSES
Check the cleanliness of the exchanger
Check the operation of the temperature sensors
Check the temperature sensor connection
H.01
.08
Flow temperature increase in heating mode too quick.
INSUFFICIENT CIRCULATION
Check the boiler/installation circulation
Activate a manual venting cycle
Check the installation pressure
Check the operation of the pump
OTHER CAUSES
Check the cleanliness of the exchanger
Check the operation of the temperature sensors
Check the temperature sensor connection
H.01
.14
Maximum flow or return temperature value reached.
INSUFFICIENT CIRCULATION
Check the boiler/installation circulation
Activate a manual venting cycle
20
400 Combi 2